A video camera which applies chromatic aberration to focus a subject image obtained through a lens is known (refer to Patent Document 1).
However, the video camera disclosed in Patent Document 1 can rapidly focus on a subject image which has previously been focused on, but cannot rapidly focus on a subject image which has not previously been focused on. That is to say, there is a problem in that the video camera disclosed in Patent Document 1 cannot rapidly focus on a subject image.